I don't have a SP but run MR front and M3 UL on the rear on by BP. I really like this setup it's fast loose enough and has good drive. I would not like to go bigger on the rear tho. I did have a set of Gx side bite rears but it was too skittish on bigger waves.
I just started using SA 2 on my sp I am 5'9 170 lbs the larger quad set up works really good for drive speed and arching turns, good snaps too, overall good set for the wide tail hybrids. Before I was usin AI for everts on the front gx trailers on the rear, these were super fast but don't hold as well as th SA 2.
Just got Stretchís new S3 fin set (stretch controllers). I have ridden them on both the PN and the SP and they work crazy good. They are crazy fast right out of the gate, havenít missed a section yet and the back fins give the pivot needed. The s3 fin set creates so much drive itís insane. It looks like itís going to be too much fin but they are so rad. The bigger fins have allowed me to ride the SP in shoulder high waves.
Stretch has these fins made by Fins unlimited down in San Diego so you know there is no question about quality (made in America is a plus). Stretch has these fins made for his Buzz models, which have a deep double concave just like the SP. Itís magic when you ride a fin set that was designed for your type of board. They are like Future controllers but with a better inside custom foil and fuller tip. They are making two sizes for big and small riders. I have been riding stretch fins for a while now but these are the best fins for this type of board with deep double concaves in the tail.
They are a bit pricey at $120 but after that first pump and you feel the speed, trust me itís worth it. You have to buy from stretch online store because no shops have them yet.